1. Field of the Invention
The invention relates to a casing (i.e., housing) for receiving an electrical device, particularly a switching device or sensor, having at least one indicating or display apparatus for indicating or displaying different electrical states, particularly switching states, of the device, according to the preamble of claim 1.
The invention also relates to a casing for receiving an electrical switching device or sensor with an indicating device for indicating different electrical switching states of the electrical switching device or sensor, said casing being shaped in a substantially cuboid or cubic manner.
2. Description of Related Art
Numerous casings for receiving electrical switching devices or sensors are known. The casings have indicating devices for indicating different electrical switching states for monitoring the functionally correct operation of the electrical switching device or sensor. For example, DE 19512915 discloses an electrical connection part with electrically contacting contact pins or female contacts, such as plugs or sockets, which has a reception part in which is placed a light guide member made from transmissive material with at least one illuminant and through which are passed leads for the contact pins. The light guide member has arms, provided on their abutting ends on the side facing the illuminant with, in each case, a surface plane-inclined or curved in the direction of the longitudinal axis of the main radiation direction of the illuminant, which, in each case, form the reflecting deflecting surface of the arm and which are able to deflect the light mainly in the axial direction within the particular arm at an angle between approximately 40° and 140°, preferably at right angles to the main radiation direction thereof. The reflecting deflecting surfaces of the arms collide in each case in the axis of the main radiation direction of the illuminant in a point or edge directed towards the light guide member. Below the point or edge, the light guide member has a recess in which is located the illuminant.
This apparatus, like most of the known casings, suffers from the disadvantage that despite indicating the switching state of the electrical switching device or sensor, the switching state cannot be seen to the same extent from all spatial directions, so that in certain circumstances, a fault or a malfunction of the electrical switching device or of the sensor can occur without it being immediately noticed by an operator.
Additionally, FR 2643640 discloses a proximity switch with an illuminant, for example, a light emitting diode, being positioned in a transparent end piece. With the aid of this transparent end piece and a plurality of reflections obtained by this means, an improved visibility of the illuminant is obtained.